LRP1 and glioma: Low‐density lipoprotein receptor‐related protein‐1 (LRP1) mediates multiple ligands across the BBB and is abundantly expressed in gliomas, while Angiopep‐2 (Ang) is a targeting peptide with a high affinity for LRP1 and trans‐activator of transcription (TAT) is an efficient cell‐penetrating peptide.